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N ov. 22, 1932. M. A. POWERS LIQUID FUEL BURNER IGNITION I Filed June 1o, 1929 ///5 HTTOENEY.

50 install', requires no special control and is very Patented 151611.22, 1932 vUNITED `s'mras PATENT OFFICE MILTON A. POWERS, OF DETROIT, MICHIGAN, ASSIGNOR T0 THE TIMKEN SILENT AUTOMATIC COMPANY, OF DETROIT, MICHIGAN, A CORPORATION OF MICHIGAN Y mQUnJ'rUEL-nunm IGNITION' Application led June 10, 1929. Serial N0. 369,863.

My invention relates to the ignition of liquid fuel burners and is particularly adapted to the ignition of burners of the vertical rotary type in which ignition takes place around the periphery of a refractory hearth member. Heretofore gas pilot lights and the like have been the common means for lighting such burners; but there area number of ob-V jections to this general method., among which' are its instability, cost, and limited application.

In some types of oil burners, 'electric ignition is easily possible as'there is some point in the combustion zone where a readily ig nitable mixture may always be found and in which a spark gap may be located. On the Vvertical rotary burner, where combustion takes place at a distance from the rotating head, this condition does not exist. The oil is ordinarily thrown in a finely divided state to the periphery of the refractory combustion surface where it is volatilized, mixes with t he accompanying air and burns. The conventional electric spark will frequently ignite this mixture when the refractory is hot but l very frequently fails to'ignite the mixture when the combustion chamber has completely cooled. A number of methods have been under development and probably the most suc-l seriously a ects'the heating and'an additional high voltage circuit with a suitably located spark gap may be added to insure `fiashing of the vapors'. It is evident that these systems are involved and require complicated control systems as the element must be heated before the burner can be started. In'addition the current required is often' excessive particularly during the starting of the burnervmotor.

It is' very evident that the simplest and best ignition system would be a jump spark properly located if it could be made to function; Such a system is cheap to make and reliable electrically and may be as universal in its application as the burner itself. Man attempts have been made toutilize a spar gap for ignition at the refractory ring and the results have been most discouraging. The spark between the electrodes, is extended by the velocity of the air, and while a very hot spark may be used .the heat is not conserved but is dissipated into the air stream. The oil spray passes between or near the electrode and'while at times it vmay be momentarily ignited the high velocity prevents iame propagation and failure results.

The present invention, therefore, has for its principal objects to conserve the heat of the electric spark and to maintain a supply of liquid fuel in proximity to the hot spark, thereby to make the ignition system reliable and dependable even when the combustion chamber has completely cooled. A further object is a simple and durable-electric ignition system for such burners. Still further objects and advantages will appear herein-A after.l

Withthe foregoing and other objects in view, the invention consists principally in an electric ignition means in which one electrode is heated, as by electricity; in which a Vsupply of liquid fuel'is maintained in close proximity to the heated electrode, in which liquid or vaporized fuel is sprayed onto the heated electrode during the operation ofthe burner,

in which the 'heated electrode is made consid-'1 erably larger than the non-heated electrode and in which the heated electrode is made of refractory material or is embedded in refractory material, as in the surface of a refractory hearth member. The. invention further consists in the ignition apparatus and process and claimed.

In the accompanying drawing, Fig. 1 is a diagrammatic top plan view of an oil burner and an ignition apparatus embodying my invention,

Fig. 2 is a sectional'view on the line 22 of Fig. 1,

(Non a larger scale) Fig. 3 isa sectional view on the line l and in the parts and combinations and arrangements ofrparts hereinafter described of Fig. 1 showing the-ignition apparatus in detail, n

Fig. 4 is a perspective View of the. ignition apparatus shown in Fig. 3 and of the refractorFy hearth -member in which it is mounted, ig...5 is a sectional view similar to Fig. 3 sliowing a'modied form of the invention, an y Fig. '6 is a view similar to Fig. 4 "showing another modified form.

Apreferred embodiment of the invention is shown in Fig. 1 in which the conductor wire 1 of one electrode A is mounted in a suitable insulator 2 embedded in one of the re` fractory members 3 of the peripheral ring of the hearth, said electrode being connected by a wire 4 to a suitable-,high tension transformer (not shown in the drawing). In the above type of burner the spray is projected from the rotating burner head along the lines tangent thereto and, in order to reduce the amount of spray that collects upon the exposed upper end of the conductor wire'l of the electrode A, said end of said conductor wire is preferably disposed along a line substantially tangent to said burner head. The other electrode b is provided with a suitable insulator 5 embedded in said hearth member?) and with a wire 6 which also leads to the transformer.

Both insulators 2 and 5 extend through the portion ofthe refractory hearth floor 7 on which said hearth ring 3 is supported. The second electrode B has an elongated conductor wire 8 which is disposed in a block 9 set into the sidewall of said refractory hearth member 3 and conforming to the surface thereof. Said block 9 may be made of metal but in the preferred form is composed.prin cipally of carborundum or some other material that is refractory and is also a conductor of electricity. ',Said wire 8 is preferably of serpentine shape', so as to have extended electrical contact with the block and (in the case of carborundum or the' like) to reinforce said block.

' The transformer may be of any desired type but is preferably of such capacity as to roducea relatively high secondary current.'

t has been found very satisfactory to have the transformer operate at 10,000 volts and to make the power input to the transformer about 100 watts,`which is much 'greater than the power input Aheretofore used. This increased power input results in a flaming arc at the spark gap having considerable heating 60 electrode B, greatly aiding in the ignition of the fuel. Liquid fuel accumulates on the surface ofthe refractory lelectrode B where the heat of the electrode tends to volatilize the oil while the-passage of the flaming arc through the layer of oil to the electrode wire 8 beneath makes ignitioncertain.

Y preceding description.

The extent to which the'carborundum heats may be controlled not only by regulation of the spark, but also by modifying the composition of the carborundum block 9as by mixing with the carborundumcement from which the block is made, any desired quantity of some refractory material that is not a conductor of electricity, refractory clay, for example.

While Lthe preferred embodiment contemplates the use of an electrode B including a carborundum Iblock 9 set into the surface of the refractory hearth, satisfactory lresults can also be obtained by mounting one electrode B so that its conductor wire 8 is dihearth ring 3 and spacing the other electrode A slightly therefrom. Such a modification is shown in Fig. 6. y,The electrode B that is placed against the hearth is preferablyT considerably larger than the other electrode and is of serpentine shape. Liquid fuel coly rectly against the surfaceof the refractory lecting on saidelectrode B and on vthe hearth in close proximity to the electrode is much more easily ignited than by. ignition devices now in use. l

Where it is not feasible to modify the -hearthconstructiom as in the'preferred embodiment, or to mount one electrode on thel surface of the hearth,'it is possible to place on one electrodeB some material as asbestos'10, vthat will tend to collect liquid fuel.

Such a modification is illustrated in Fig. 5.-

The passage of the spark through this fuel soaked material will facilitate the ignition of said fuel. l

The herein described invention has numerous advantages which are evident from the and the arrangement whereby one electrode is in close proximity to an accumulation ofl liquid fuel make the'operation of the igniting device quick and certain. f While. the above process are particularly .adapted for use in The flaming spark described apparatus and ioo connection with vertical rotary oil burners'- now commonly used for heating houses and other buildings they are also adapted for use in liquid fuel burners generally, no. matter for what purpose such liquid fuel burners are used. l f` t -As numerous changes may be made in the above construction and different embodiments of the invention made without departing from the scope thereof, itis t be clearly understood that my invention is not limited to these details of construction but is capable of other adaptations and modifications with- 'in thescope of the appended claims.

What I claim is:

1. An electric 'ignitor system for oil burners of the kind having a non-metallic refractory hearth ring,'coinprising a transformer, a pair of electrodes constituting the ignitor gap of the 'transformer circuit, both elecseason trodes being supported in fixed relation in a segment of the hearthring.

2. An electric'ignitor system for'oil burn#v tric ignition system comprising an electrodel of-carborundum andl refractory cla having an electric conductor wire embedde therein.

5. The improvement in Aliquid fuel electric ignition vdevices for burners `of the vtype -wherein ignition and combustion take place around the periphery of a hearth member to which fuel is sprayed by a rotary head disposed centrally of the hearth, which comprises a stepped hearth ring, the surface of the lower step being above the level of the hearth floor, said lower step havinga continuous groove in its upper surface, and fixed spaced electrode members adjacent to said groove.

6. The improvement in liquid fuel electric i fiton devices for' burners of the t pe w erein ignition and combustion take p ace around the periphery of a hearth member to which fuel is sprayed by a rotary head disposed centrally of the hearth, which comprises a"`s'tepped hearth ring, the surface of -ers of the kind havin with an upstanding ri aroundv its outer pe-4 the lower step being above the level of the hearth floor, said lower step having a con` tinuous groove in its upper surface, and fixed spaced electrode members adjacent to said groove.

7. An electric ignitor system for oil burna refractory hearth riphery and means for spraying oil toward` said peripheral rib, comprising a transformer of at least 100 watts input and 10,000 volts output and a pair of fixed electrodes con-l` stituting the ignitor gap of the transformer circuit, said electrodes being mounted at the inner face of said rib.

8. An electric ignitor system for oil burners of theV kind havin a refractory hearth with an'upstanding' ri around its outer lperiphery and means for spraying oil toward said peripheral rib, comprising a transformer of at least 100 watts input and 10,000 volts' output and a pair' of fixed electrodes ycon` stituting the ignitor gap of the transformer circuit, said electrodes being mounted at the inner face of said rib and one of said electrodes being embedded in the surface of said rib.

9. An igniting device for liquid fuel electric ignition system com an'electode of carborundum 4andre actorycla having an electric conductor wire embedde therein, said conductor wire being of serpentine shape so as to have extended contact with said carborundum and clay. Y

10. A liquid fuel electric ignition system of the spark ty' e for burners wherein operation and combustion take place around the periphv ery of a hearth member to which fuel is sprayed by a rotary head disposed centrally of the"h'ea`rth, said system having an input v of 'at least 100 watts and an output at a. minimum of 10,000 volts, and includin apair of fixed spaced electrodes located at t e periphery of said hearth, one of said electrodes being of refractory material.

11. A liquid fuel electric ignition system of 'l the spark type for burners wherein operation and combustion-take place around the periphery of a hearth member to which fuel is sprayed bya rotary head disposed centrally of the hearth, said system having an input of' atleast 100 watts and an output at a, minimum of 10,000 volts, and including a pair of lfixed spaced electrodes located at thel peri hery of said hearth, one of said electrodes b refractory material having such electrical resistance Ias to be heated upon passage of the sparking current therethrough.

12. A liquid fuel electric ignition system of the spark type for burners wherein operation and `combustion take place around the periphery of a hearth member to; which fuel is sprayed by a rotary head disposed centrally of the hearth, said system having an input of" at least 100 watts and an output at a minimum of 10,000 volts, land including a pair`of fixed' spaced electrodes located at the eriphery of said hearth, one of said electr es'exposing a. relatively small surface to the ignitable mixture and the other a relatively large sureingof v unsi face of said mixture to interce t and collect i' a portion thereof, said second e ectrode being composed of electrical resistance material that becomes heated from impingement of electric spark thereon and passage of current there'- through.

13. A liquid fuel electric ignition system of y the spark type for burners whereb ignition and combustlon take place around t e periphery of a hearth member to which fuel is sprayed by a` rotary head disposed centrally of -the hearth, said system having .an input of at least watts and an out ut, ata minimum of 10,000 volts, and having apair of fixed spaced electrod's'disposed at the pey riphery of said hearth.`

Signed at Detroit, Michigan, this 3rd day MILTON A. POWERS'.

CERTIFICATE on CORRECTION.,

Pampa." 1,888,691 November zz, 1932. MiL-'roN A. romans.. j l

It is hereby certified thaterror appears-iin the printed specification of the above numbered patent requiring correction asiollows: Page 3, line 42, claim.

6, after "'roove" insert the comma and words l", one of said electrodes being shaped idd located to intercept the iuel sprai and collect a deposit thereof";

and that the said Letters Patent should be read with this correction therein thatv the same may conform to therecord of the case in the Patent Office. Signed and sealed this 247th day of'Dccember, A.- D. 1932.

vM; J. Moore, (Seel)A r Acting Commissioner voi Patents. 

